Draft gear



Dec- 18, 192s.l

E. G. GooDwm DRAFT GEAR Filed July 11. 1924 INVENTOR E .ci Goo ow' N BY y Patented Dec. 18, 1928.

UNITE-n sTATEs PATENT OFFICE.

ERNEST G. GOODWIN, OF PETHAM, NEW YORK, ASSIGNOR TO STANDARD COUPLER COMPANY, QI NEW YORK, N. Y., A CORPORATION VOF NEW JERSEY.

DRAFT GEAR.

ppneation med Jury 11, 1924. serial No. 725,447',l

This invention relates to draft gears and has for its object the provision of a substantial, self-contained draft gear of relatively high capacity and comparatively long stroke.

`A further obj ect of the invention is the provision in such a gear of members having nonplane .faces in order to increase the frictional area and at the same time to aid in theoperation of the device and also to give* added strength. A still further object ofthe invention is the provision of anchoring mem` bers for the side wedges through the' medium of which it is possible to assemble and install the spring barrel with its wedges in a car more conveniently than is possible with the average gear. Other and further objectsof the invention will be apparent from the following description, and are particularly set forth in the claims.

In they drawings :'w-

Figure 1 isV a horizontal longitudinal' section of a portion of a railway draft rigging showing' my improvement in connection therewith.

Figure 2 is a vertical section taken on the line 2-2 of Figurei'l.

Figures 3* and 4 areI sections taken on lines 3-3 and 4 4 of Figure 1, showing the contour of the contacting frictional faces respectively, of the block and centerwedge and of the block and friction box.

FiUur'e 5 is a pers ectiveof a slightly modified form of outer riction wedge or block;

Figure 6 is an elevation of a modified form of spring barrel friction box, of a type to coA operate with the block shown in Figure 5;

In the drawings the numeral 1 denotes the two long channeled draft or center sills of the` car to each of whichis attached a rear stop member 2 and a front stop member3, between which are placed the friction shock absorbing member including the frontfollower It and thespring cageor barrel with its wedges and springs, these parts being'within the custom* ary yoke 5 and supported in operativeposi'- tion by theV saddle or supporting platet detachably secured to the two center sills y1f. A portion of the drawbar is shown at 7`,"thi`s being connected bythe usual cou ler key 8 to the forward portions 9 of theyo e5. These various parts bearing numerals below 2 10 are illustrated merely toshow the general assembly, the present invention relating entirely to the spring'barrel and its wedges.

The spring barrel 1'0 is of a configuration .in cross-section best seen in Figure 2. The barrel isv substantially rectangular and has strengthening ribs 11 at the sides and considerabl-y higher ribs 12 at the top and bottom. lThe rear end of the barrel'is entirely open for the full size of the bore and .ends in a rectangular flange', strengthened, in addition to the full. length ribs 12, by the triangular strengthening ribs 14, between which and i i proxi'mately horizontal faces 19" and 2O at the sides, and sloping walls 21 at the top and bottom, these top'andl bottom walls in the preferred constructionbeing curved as shown in Figure l, but the invention also contenirV plates the use of plane or substantially plane,

sloping friction faces, asslrown in the modified box of Figure G. In the preferred form the curved surface of the box is concave and the radius of the curve is relatively great at the center' and decreases" in length toward" thev sides. Thecurve of each friction face merges' with" the plane side faces bysubstanti'al curves which make it possible t'o` round out the corners of the barrel or box, materially adding tothe strength of same, this beingimportant, as' itis intended tomake the-combined box and barrel of cast steel and' this casting, by virtue of t'l'ie curving of the friction faces with the shorter radius near the corners, may be made of a; thickness which corresponds close* ly tothe strain at all points.

In both the preferred form and in the modification shown inV Figure 6, the friction faces of the box are each provided with an anchoring rib 23 ending flush' with the frontl face'of the friction box but terminating short of the rear edge 25 of the box, thereby forming a shoulder 26, which, when the device is expanded to full release contacts with a nshoulder 27 forming the rear end of the groove 28 in the cooperating outerfriction wedge or block 30. As seen in Figure 4 the friction faces 32 of the side blocks correspond exactly in their irregular curve with the curve of the faceV of the friction box, and obviously these ssi curves are necessarily struck in a plane at right angles to the respective friction faces in order that there shall be the same tit of the elements at all points of travel of the gear, as is quite clearly shown in Figure 4.

The center wedge 34 is generally of the well-known type except that its faces engage ing the two side wedges 3() are curved. Unlilre the curve of the friction box face and the outer face of the side wedges, which, as shown in Figure t is nearly flat at the center and has its radius grow shorter and shorter towards the two sides syn'imetrically, the curve of the center wedge faces is constant or has one radius, as shown in Figure 3, in other words the cooperating faces of the center wedge and the two side wedges are each sections of a true cylinder, this being necessary in order that the side wedges may shift around the center wedge and adjust themselves vto the friction box, thereby avoiding thc possibility of the wedges being tight on one side and loose on the other. This con- 1liguration is also advantageous in view of the fact that the spring is circular while the box is rectangular, so that the curves just described tend to equalize the thickness of all of the part-s although the contour is gradually changing from a circle to a rectangle.

The center wedge is counterbored to receive the central spring 35 and the intermediate spring 36; the outer spring 37 engaging the center wedge 34 near its periphery, and the center wedge being enlarged'upwardly and downwardly, respectively, at the rear `of the top and bottom in accordance with standard practice.

rlhe provision of the anchoring means, consisting of the shoulders 26 and 27, together with the separable bottom to the barrel, render the installation of the device in a car quite simple. The side wedges or friction blocks and the center wedge are placed in the box firstrand some small object is then placed between the contacting faces of each of the anchors in such a way as to hold the gear assembled in a space slightly shorter than that into which it is to be placed. This materially simplifies the application of the gear to the car and in no way detracts from its efficient operation, as the small inserts will fall away when the gear is closed the first time. Instead of inserting an entirely new piece between the retaining shoulders a smallrib 38v can be cast on the shoulder of the side friction block of sufficient size to resist the light static spring load but not large enough to resist shocks, soon disappearing after the gear is put into service.

What I claim is:

1. In a friction draft gear a spring barrel, a. friction box, a. block frictionally engaging said box, and a spring urged wedge frictionally engaging said block; said box and block having ninterengaging surfaces, one of said surfaces being concave while the other is convex, each curve having an average radius greater than the distance from the center of the gear to the outside surface of the spring barrel. f

2. In a friction draft gear a spring barrel, a friction box. a block frictionally engaglng said box, and a spring urged wedge frictionally engaging said block; said box and block having curved interchanging surfaces, one of said surfaces having a rib thereon and the other surface having a groove therein receiving said rib, said rib and groove each having a shoulder, said shoulders contacting to limit relative movement.

3. rIhe combination with a spring barrel fora friction draft gear, consisting of a gcnerally rectangular casing having an entirely unrestricted open rear end and an open front end restricted by sloping friction surfaces, the minimum space between which is less than the eorrespomling diniension of the bore of the barrel, of a plu ality of wedges be tween said surfaces, an end plate entirely closing the rear end of said casing and sc-V .1.

cured thereto, a spring interposed between said end plate and one of said wedges, and means carried by the remaining wedges and by said surfaces for limiting the outward movement of said wedges, and temporary means for` still further limiting such movement.

4; In a device of the character described, a friction box having a plurality of inwardly converging walls, a longitudinal guiding rib centrally of each wall, and terminating short of the rear edgethereof to form an anchoring shoulder. y

5. In a device of the character described, a friction box having a plurality of inwardly converging walls, a narrow guiding rib extending from each wall and terminatingr shortof the rear edge thereof to form an anchoring shoulder, friction blocks cooperating therewith, each block having a groove in its friction box engaging side extending from an edge of said side to a point. short of the opposite edge, `thereby forming a shoulder to engage the anchoring shoulder of said rib, and menas for resiliently holding said blocks in contact with said box.

6. In a device of the character described, a friction box having a plurality of inwardly converging walls, a plurality of friction blocks each contacting with one of said walls, means for rcsiliently holding said blocks against said. box and for permitting their contacting frictional faces to slide one on the other, a rib extending from one ot said frictional faces and terminating in a shoulder, a shoulder on the contacting frictional face adapted to engage the rib shoulder to limit relative movement of the block and box, one of said frictional faces being concave and the other face being convex.

loo

7. In combination a spring barrel open at oneend, a bell month friction boX therefor, a detachable cover for said open end, sliding friction Wedge members Within said boX, means including a plurality of pairs of opposed shoulders for limiting the outward movement of said members, one shoulder of each pair nicving Within the bore of the barrel upon inward movement of the members whereby a chock may be inserted between the opposing shoulders before the cover is attached to limit temporarily still further the outward movement of said members, thereby to facilitate the assembly of the gear in a yoke.

8. A Wedge for a friction draft gear having a groove therein to receive a travel limiting rib on the cooperating Wedge, an-d a relatively fragile rib in said groove to limit still further the travel of the Wedge until said fragile rib is destroyed by the shocks incident to service.

9. In a draft gear, a casing having a friction member, a spring Within said casing, a plurality of friction members held by the spring in engagement with each other and with the friction member of the casing, one of the friction members having a groove therein and another of said friction members having a rib thereon to slide in the groove and to limit relative travel of the members, a fragile rib on the grooved member of sufficient strength to resist the light static load of the draft gear spring but not of sufficient strength to withstand the shocks of service, said fragile rib limiting still further the relative movement of said friction members.

l0. In a friction draft gear, a casing, a friction box, three cooperating Wedges, one a center Wedge and the other tivo each side Wedges, a spring Within said casing engaging said center Wedge and also the Wall of the casing distantfrom the friction box, the engaging faces of the center wedge and the two side Wedges being cylindrical, and engaging faces of the side Wedges of the friction box being curved.

ll. In a friction draft gear, a barrel having a substantially rectangular main portion, a cylindrical spring, av friction box, a center Wedge, a plurality of side Wedges, the interengaging faces of the center and side Wedges being smoothly arcuate and the interengaging faces of the side wedges and of the box being curved irregularly, the radius of the curve being greatest at the center and growing less tcivard each side.

In testimony whereof I aiiix my signature.

nRNnsr e. eooDWrN. 

